Diaphragm-actuated mechanism



April 28, 1925. 536,035

JL 'rwARDowsKY DIAPHRAGM ACTUATED MECHANIVSM Filed Aug. l5, 1923 l KN 4 Patented Apr. 28, i925.

JOHN Vriwvaanowsnv,

OLE CHICAGO, ILLINOIS. i

IAPHRAGM-ACTUATED `MECHANISM.

Application filed August 13, 1923. Serial `No. 657,26S.

To all 'whom t may concern.'

Be it known that I, JOHN TwARDowsnY, 'citizen of Russia, residing at Chicago, in the county of Cool; and 'State of Illinois, 5 have invented certain new and useful Improvements in a Diaphragm-Actuated Mechanism; and` I do hereby declare the following to be a full, clear, and eXact description of the invention, `such as will enable others skilled the art to which it appertains to malte and use the same.

My invention relates to diaphragm-actuated mechanisms and in its general `objects aims to provide simple and effective means for limiting the flexing of a hollow diaphragm so as vto prevent undue pressure variations from imparting permanent set to the diaphragm. Furthermore, my invention provides' pressure-transmitting means arranged for permitting theemployment of a hollow diaphragm of relatively large diameter, thereby securing a highdegree of sensitiveness in proportionto the available power. It also provides a simple mounting arrangedyfor retaining the pressure-transmitting means in operative position and also arranged for limiting the flexing of both faces of a hollow and relatively short diaphragm `without interfering withwthe responsiveness of the diaphragm to variations in pressure. Still further andl also more detailed objects willappear from the `following specification and from the vaccompanying drawings, in which Fig. 1` is a central and vertical section through the actuating portion of a diaphragm-actuated switch ofa kind suitable `for controlling a supply of current to a mechanical refrigerator in response to the pressure `in the expansion coil of the refrigerator. y

Fig. 2 is a plan view `of the same mechanism taken from below the upper guard member, or `along the line 2 2 ofr Fig. l.

Fig. 3 isa fragmentary vertical and central section through the diaphragm and the adjacent portions of the mechanism, showing these parts as they appear when the pressure within the diaphragm is considerably r P0 below` the pressure of the outside air, or in other words when the diaphragmfis contracted. y, 4 is a sectionI similar to Fig.` 3 but showing; the diaphragm as it appears when In one ofits immediate commercial applications, my invention is particularly suited for use in controlling the circuit of an` electric motor employed as part of a vmechanical refrigerator, so as to stop the operation of the motor automatically when the temperature within the, .refrigerating chamber falls to a certain point and so as to restart the motor whenever the temperature rises beyond this point. For this purpose, I have disclosed a suitable switch in my applica,d

tion #524,991, filed Dec. 27, 1921, on a ther-l i mally Vresponsive electric switch. In this application, I am picturing and describing a switch responsive to `pressure variations in a hollow diaphragm, this diaphragm having Vits interior connected to a tube disposed within the refrigerating,chamber and containing a controlling fluid which vaporizcs at a temperature approximating that which is to be maintained in the refrigerating chamber, sothat the variations in the extent of the vaporizing of the fluid within the tube will produce corresponding pressure changes within the interior of the hollow diaphragm.` a i While mechanism for this purpose can `readily be constructed after the manner shown lin my said accompanying application so as to be fairly sensitive to temperature variations in the refrigerating chamber, the `apparatus must also be able to withstand "the much greater temperature differences and corresponding pressure differences in the diaphragm ywhich occur when the refrigerator is `not in use. Thus, while the variation in pressure differences within the hollow diaphragm may be relatively small during the normal operation of the refrigerator, these differences are greatly in-l creased when the refrigerator is standing idle at the factory or in transit, as the resulting increase in temperature vaporizes an abnormal portion of the controlling fluid and hence creates an abnormally high pressure within the hollow diaphragm, thereby tending to flex the diaphragm to such an 'exuo y tent as to impart a permanent set to its walls.

My present invention aims to overcome this diliiculty and also aims to provide simple means tor limiting the flexing ol the diaphragm to certain portions thereof, thereby permitting the effective use oit diaphragms of such increased diameters as will altord trie desired sensitiveness ot action. For this purpose, I provide a mounting for the diaphragm which includes guard formations adapted to be engaged to an increased extent by the opposite iiaces ot a relatiyely flat hollow diaphragm during the expansion of the rallye, and I also en'iploy a pressure-distributing member arranged for limiting the flexing ot one tace otl the diaphragm to its radially outward portions. Furthermore, I provide a mounting which will readily hold the pressutie-transmitting member in operatireA position, ,which will permit the spacing .between the guard portions ot the mounting to be yiaried if desired, and which will readily permit access to the diaphragm vtor an in spection oi the latter or lior any other purpose.

In enrploying such a mechanism tor the general purpose described in my copending application, I connect one end of the control tube l which houses the controlling tluid through the bore ot a cup 2 to the interior ot a hollow diaphragm comprising a pair o'p approximately parallel disks 3 and d con nected by an approximately cylindrical wall 5, the upper diaphragm tace l being imperit'orate while the lower diaphragm face Shas a perforation which houses the mouth portion ot the cup 2 and is sealed to the latter.

'lhis mouth portion of the cup 2 extends through a bore in a base plate t3 which normally bears at least along its radially inner poi-tion against the bottom disk 5% of the diaphragm, while an upper guard 7 is disposed aboi'e the base plate 6 and spaced from the latter by hollow bushings 8, the guards 'i' and (S being rigidly secured vto each other by screws 9 which extend respectively through the bores ot the spacer .bushings 8 and which clamp these ybushings bejtweenthc two plates.

The upper `guard T vdesirably has integral with it an inverted cup portion IO which is bored out and Ithreaded at its upper end to receiye an adjustable bushing ll.' Thisbushing' has a bore aiiording a ,guide lior the phjmger l: employed 'tor transmitting` the variations inthe iiexing off the diaphragm, and a pressure-transmitting disk 13 isr desirably interposed between the lower end of .tais plunger l12 and the upper wall 4. of the diaphragm. 4rLlhe hollow cup lO'also houses a' compression spring 14 which bears at its lower end against the disk 13 and at its upper end vagainst a washer 1l5y engaging the lo ver end o t the lbusliing ll. The spring la cooperates with the pressure of the outer air in resisting the expansion ol' the diaphragm and can be adjusted as to the extent of this cooperation by screwingV the bushing lil further in or out, thereby permitting the etliective out-er pressure to be adjusted so nearly equal tothe internal pressure Within the diaphrao'm under operating conditions as to n'xake the diaphragm quite sensitive in action. Then the resulting movement of the plunger l2 is transmitted through a lever 16 to any desired mechanism which is to be operated by the expansion or contraction ol5 the diaphragm.A To hold the pressuredistributing disk 13 central, the lower tace ot' the upper guard 7 has a recess slidably housing this disk and desirabtly ot a depth corresponding to the thickness of this disk.

lith the parts thus arranged, it will be obvious that the disk 18 limits the flexing ot the upper or impertorate wall of the diaphragm substantially to the portions of that wall which are outward of the disk. I'Iowever, thisV disk does not interfere with the flexing oit the said outward portions oi the upper diaphragm wallet, nor with -the ilexing of the lower diaphragm wall 3. In practice, a considerable reduction of pressure within the hollow diaphragm causes the combined etlect of the outer air pressure and ot the spring l-t to compress the diaphragm to the position shown in full lines in I'ig. 3, or even that shown in dotted lines in the same figure, while a decided increase in the pressure within'the diaphragm above the combined pressure etlect of the external air and of the spring lei-will cause the diaphragm to expand to an approximately elliptical section somewhat alt'ter the manner shown in Fig. d. then thus expanded, the lower wall 3 oi' the diaphragm engages they top of the lower guard plate 6 to an extent increasing radially outward ot this wall the pressure increases, vand the same holds true as to the engaging of the upper guard 7 by the top diaphragm wall il. Iy suitably spacing the two guarls 6 and 7, which can readily be done 'by selecting bushings 8 ot' suitable height, I can limit the expansion of the diaphragm quite effectively, so as to avoid haying the upper and lower diaphragm walls tlexed to such an extent that they would not readily be flexed back when the applied pressure is disconti'ryuiied.

By using spacer bushings 8 which lbring the guard." glfairly close to the opposite rtaces ot ithe diaphragm, I can readily limit the flexing of the diaphragm walls in this simple manner, while employing a diaphragm of such a diameter as to insure both .the needed actuating thrust on the plunger l2 and' the desired sensitiveness of action. Indeed, I have found in practice that by this arrangement I can readily employ a diameter of say 5 inches diameter with a -iinch height, and can make a diaphragm of this lll) ` 8 I can vary the extent of the-flexing, there- `by adapting my arrangement to diaphragms made of different metals or different thick nesses of the samemetal, and that I can fur- Ither control the flexing by varying the size ol the pressure-distributing disk 13. It will also beevident that the movement imparted `to this disk can be transmitted in anydesired manner and for any desired purpose, hence I do not wish to be limited to the employing of my apparatus in connection with an electric switch. Nor do I wish to be limited to the various details of construction and arrangement above describedsince these might obviously be modied in many ways without departing either from the spirit of my invention or from the appended claims. For example, the pressure transmitting disk might `be omitted, as `shown in Fig. 5,which figure pictures an arrangement in which the compression spring 14 and the plunger 12 both are in direct engagement with the upper wall 4 of thehol-` low diaphragm, and which also pictures the upper and lower guards 17 and 18 as spaced from each other by suitable offset portionsintegralwith these guard plates and forming peripheral flanges which.` are secured to each other by rivets 19.

I claim as my invention 1. The combination with a hollow diaphragm of the general nature of a shallow box having relatively flat heads adapted to be convexed away from each other by Huid pressure within the diaphragm, of a support attached to one head; and a guard supported by the other head; the guard in` cluding a pair of guard plates respectively adapted to limit the convexing of the two heads of the diaphragm, and spacing means interposed between the guard plates and free of engagement with the diaphragm.

2. The combination with a hollow diaphragm of the general nature of a shallow box having relatively Hat heads adapted to be convexed away from each other by lfluid pressure within the diaphragm, of a support attached to one head; anda guard supportedby the other head; the guard including a pair of guard plates respectively `adapted to limit the convexing of the two heads of the diaphragm, and spacing means interposed ybetween the guard plates and free of engagement with the diaphragm; and means interposed between the said other head and the guard plate adjacent thereto for holding the said other head out of engagement with `the last named guard plate until a predetermined pressure has been reached within the diaphragm. y'

3. The combination with a hollow diayphragm of the general nature of a shallow box having relatively Hat heads adapted to be convexed away from each other by fluid pressure within the diaphragm, of a support attached to one head, a pressure distributingdisk engaging theother head, and a guard supported by the disk and including two rigidly spaced guard plates respectively adapted to engage the heads `of the diaphragm so as tov limit the conve-Xing of the said headsto areas increasing radially of the heads as the pressure within the diaphragm is increased.

4. The combination with a hollow diaphragm of the general nature ot a shallow box having relatively flat heads adapted to be convexed away from each other by fluid pressure within the diaphragm, of a support attached to one head; a- Vpressure distributing disk engaging the other head, a spring supported by the disk, and a. guard supported by the spring and including two rigidly spaced guard plates respectively adapted to engage the outwardly directed faces of the two heads.

5. "The combination with ahollow diaphragm of the general nature of a. shallow box having relatively flat heads adapted to be convexed away from each other by fluid pressure within the diaphragm; of a support attached to one head; a pressure distributing disk engaging the other head, a spring `supported by the disk, and

a guard supported by the spring and includl ing two rigidly spaced guard plates respectiively adapted to engage the `outwardly l directed faces of the two heads. the radially outer portions of the diaphragm being continuously free of engagement with the guard, the guard plate adjacent to the said other head being recessed to permit the pressure disk to hold the said plate away from the said other'head when the pressure within the diaphragm is low.

6. The combination with a hollow diaphragm ofthe general nature of a shallow box having relatively flat heads adapted to be convexed away from each other by iiuid pressure within the diaphragm, of a support attached to one head; a pressure distributing disk engaging the other head, a spring' supported by the disk, and a .guard supported by the spring and including two rigidly spaced guard plates respectively adapted to engage the outwardly directed faces of the two heads, the guard plate adjacent tothe said other head being recessed-to permit the pressure disk to hold the` said plate away from the said other head when the pressure within the dia-` phragin is low; the pressure disk being orced toward the last named guard plate upon an increase in pressure within the diaphragm and being of such thickness as to present its head-engaging tace in a common plane ,with the iacc ot the last named guard plate 'facing the said other head. when the diaphragm is expanded by high pressure Within the latter.

7. The combination Vwith a hollow diaphragm of the general nature ot a shallow b oX having relatively .flat heads adapted to S. The combination With a hollow" diaphragm of the general nature ot a shallow box having relatively :dat heads adapted to bel convexed awa-y from each other by iiuid pressure Within the diaphragm and yhaving van inexpansibl@ radially cuter Wall, of a guard freely spaced y'from the said outer diaphragm Wall and including a ypair oi inflexible plates rigidly spaced from veach other by a distance greater than the height `of ,the said outer Wall, the-,said plates'being respectively opposite the two heads off the diaphragm and each adapted to engage the adjacent head to an extent increasing radially of the diaphragm vfrom the axis thereof as the pressure within the diaphi'agm increases; and a pressure-disti-ibuting disk interposed between one olt thc guard plates and the head adjacent thereto and movable with the last named head and adapte-d to limit the flexing oi the last named head to the radially inner portions thereof until the diaphragm has beenezipanded to a predetermined extent.

9. The ,combination with a hollow diaphragm consisting oi: a relatively short substantially cylindrical portion connecting a substantially iiat iinpertoratc disk with a substantially l'lat periorate disk, ot means tor connecting the bore oi the periorate disk to a source of variable pressuret a guard upon which the perit'orate disk rests, a second guard parallel to the first named guard, both guards being ot greater diameter than the diaphragm, and means for spacing the guards from each other by a distance slightly greater than the normal height ot the diaphragm.

10. A diaphragm arrangement as per claim 9, in which the guard adjacent to the imper'forate disk has a recess facing that disk and smaller iu diameter than the latter, and a pressure-transmitting disk slidably'housed by the recess.

l1. A diaphragm arrangement as per claim 9, in Which vthe guard adjacent to the impert'orate disk .has a recess racing that disk and smaller in diameter than th'elatter,

and a Apressure-transmitting disk slidably housed bythe recess, and of a thickness substantially equal to the depth of the recess. Signed at Chicago, Illinois, August 10th, 1923.

JOHN TARDONSKY. 

